US3663383A - Method for manufacturing painted metal sheet - Google Patents

Method for manufacturing painted metal sheet Download PDF

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Publication number
US3663383A
US3663383A US734801A US3663383DA US3663383A US 3663383 A US3663383 A US 3663383A US 734801 A US734801 A US 734801A US 3663383D A US3663383D A US 3663383DA US 3663383 A US3663383 A US 3663383A
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United States
Prior art keywords
painting
steel sheet
strip coil
coat
paint
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US734801A
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English (en)
Inventor
Shozo Matsuda
Tadashi Tanaka
Kouzou Murayama
Kunimitsu Yamamoto
Joji Oka
Royji Takahashi
Megumi Koyama
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Yawata Iron and Steel Co Ltd
Yawata Econ Steel Co
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Yawata Iron and Steel Co Ltd
Yawata Econ Steel Co
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Priority claimed from JP1967050450U external-priority patent/JPS463008Y1/ja
Application filed by Yawata Iron and Steel Co Ltd, Yawata Econ Steel Co filed Critical Yawata Iron and Steel Co Ltd
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
    • B05D7/50—Multilayers
    • B05D7/52—Two layers
    • B05D7/54—No clear coat specified
    • B05D7/542—No clear coat specified the two layers being cured or baked together
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D13/00—Electrophoretic coating characterised by the process
    • C25D13/20—Pretreatment
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D13/00—Electrophoretic coating characterised by the process
    • C25D13/22—Servicing or operating apparatus or multistep processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00—Processes for applying liquids or other fluent materials
    • B05D1/007—Processes for applying liquids or other fluent materials using an electrostatic field
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D1/00—Processes for applying liquids or other fluent materials
    • B05D1/28—Processes for applying liquids or other fluent materials performed by transfer from the surfaces of elements carrying the liquid or other fluent material, e.g. brushes, pads, rollers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D2202/00—Metallic substrate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D2252/00—Sheets
    • B05D2252/02—Sheets of indefinite length
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D2252/00—Sheets
    • B05D2252/10—Applying the material on both sides

Definitions

  • a method for manufacturing a painted metal sheet by successive- [21] APPL N04 734,801 sive paintings comprises the steps of (a) subjecting a metal sheet plated with zinc or zinc alloy to an electrophoretic treat- [30] Foreign Application Priority Data ment with a water-soluble resin series paint to provide an undercoating, then (b) painting the steel sheet having the elec- June 5, Japan tr deposited paint coating a water soluble or sglvent.
  • the present invention relates to a method for manufacturing a painted metal sheet by a method involving baking the steel metal sheet after the application of successive coatings of paint thereon.
  • a two coating one baking method in which a final painting and a subsequent baking are carried out immediately after an undercoating has been completed, while the resultant undercoat is still in the wet state.
  • the aim of the present invention is to eliminate the various drawbacks of conventional methods as the above-mentioned ones; and the basic idea underlying the present invention resides in that at first an undercoating is provided with a water-soluble paint by an electrophoretic painting step, and immediately after rinsing and wind-drying the resultant undercoat a water-soluble or solvent-soluble paint is applied to the undercoat in a proper manner and thereupon the thuspainted steel sheet or coil is baked once to produce a final product.
  • one of the main objects of the present invention is to provide a painting method, in which successive formations of two or more paint coats on the surface of a metal sheet can be carried out without interposing a baking between the undercoating and the final coating by subjecting the metal sheet to an electrophoretic painting with a water-soluble or waterdispersed paint to fonn an undercoat, because the water content of the paint for the undercoating can be made so small by the electrophoresis that the whole surface of the undercoat can be wind-dried in a very short period of time, which makes it possible immediately to apply the final coat to the undercoat in succession without baking the undercoat.
  • This method of the present invention is attended with the advantages that, as a paint of another kind can be used for the final coating, excellent anticorrosiveness and adhesiveness of the painted metal sheet can be obtained, the baking can be carried outwith one baking furnace and the painting line can be made short, which bring favorable effects on the control of equipment and of the painting operation.
  • the second main object of the present invention is to provide a painting method, in which flat metal sheet or strip coil is subjected to an electrophoretic painting with a water-soluble acrylic resin series paint to form an undercoat and immediately thereupon the final painting is carried out by applying a solvent-soluble thermosetting paint to the undercoat without baking the electrodeposited undercoat.
  • the third main object of the present invention is to provide a painting method, which is the most practical method for sucv cessively painting a metal sheet and in which a steel sheet or strip coil plated with zinc or zinc alloy (hereinafter referred to as galvanized steel sheet) is optionally subjected to a chemical-synthetic foundation treatment such as a phosphate treatment or chromate treatment before it is subjected to the electrophoretic painting. Then, the chemical-synthetically treated galvanized steel sheet or the galvanized steel sheet is dipped in an electrodepositing bath to obtain an electrodeposited undercoat. Immediately after the electrodeposition treatment, the steel sheet is dried by simply blowing air on it (without baking) and then a solvent-soluble thermosetting paint, e.g.
  • a solvent-soluble thermosetting paint e.g.
  • the electrodepositing bath to be used in the abovementioned third process step of the present invention that of the following composition is to be recommended as the most effective one, that is, a bath which is mainly composed of a water-soluble resin, containing as main ingredients lower alkyl ester of acrylic acid and/or lower alkyl ester of methacrylic acid and their ammonium salt or amine salt, and a water-soluble chromium compound added in an amount of 0.01 to 5.0 weight percent to the said water-soluble resin.
  • electrodepositing bath hereinafter referred to also as electrodepositing paint" or electrophoretic paint
  • water-dispersion series paints In conventional methods of coating metal articles with organic compounds by electrophoresis, there have been mainly used water-dispersion series paints and water-soluble watersolution series paints.
  • the water-dispersion series paint a dispersion or emulsion of high organic high molecular compound is employed, and as for the water-solution series paint alkali metal salts of the acrylic series, melamine series, alkyd series or maleic oil series compounds are employed, and many of them are already known through various patents relating thereto and others.
  • the present invention is a development of these investigations and is distinguished by the following features:
  • the first feature of the present invention resides in the novelty of the electrodepositing bath employed in the process of the present invention, in which the compounding ratio of watersoluble acrylic copolymer or methacrylic copolymer containing water-soluble chromium compound added thereto is specified, whereby it is made possible to attain an increased insolubilization reaction, the formation of a particularly excellent anticorrosive coat, an increase in electrodepositing efiiciency and an excellent throwing power and the like, when carrying out the electric-deposition in the said bath.
  • the second feature of the present invention is that the undercoat obtained by the electrodepositing paint itself not only has an excellent atmospheric corrosion resistance but also imparts an excellent working adhesiveness and anticorrosiveness to an ordinary paint coat formed on the undercoat.
  • the third feature of the present invention which is the most important feature of the present invention, is that the most serious problem any conventional anodic chemical-synthetic treatment by means of electrophoresis must confront, that is, the difficulty in treatment control caused by strong alkaline ingredients concentrated on the cathode in the conventional treatment,
  • the paint used in the electrodepositing operation of the present invention is a water-soluble organic high molecular compound such as copolymer of alkali metal salt of acrylic acid or amine or ammonium salt of methacrylic acid usually copolymerized with lower acrylic ester, preferably lower alkyl ester of about four carbon atoms or lower methacrylic ester, preferably lower alkyl ester of about four carbon atoms, and in some case further a third compound, if necessary.
  • the ester radical is not subjected to any particular restriction.
  • the viscosity of this copolymer resin is preferably less than 10,000 CPS in 30 percent aqueous solution.
  • the higher the degree of polymerization the better the working adhesiveness, anticorrosiveness and durability of the coat obtained thereby.
  • the range of the viscosity is advantageously in the range of from 2,000 to 6,000 CPS. This range is the most suitable from the points of working adhesiveness and other properties of the deposited coat, and an amount of electrodeposition and a rinsing effect.
  • the alkali salt in the copolymer is necessary to be less than 50 percent from the stand point of properties of the coat obtained, but is usually used in an amount of about 3 to 5 percent from the necessity of water-solubilization.
  • Metals to be treated in the bath used in the process of the present invention cover iron and steel products, that is, iron and steel themselves, melting zinced steel sheet, electro-galvanized steel sheet, tin-plate sheet, aluminum-plated steel sheet, turnplate sheet. More precisely, the electrophoretic treatment of the present invention is applied not only to the surface of iron and steel sheet, but also of aluminum-, zincor tin-plated steel sheet and, more advantageously to zincor zinc alloy-plated steel sheet which is further coated with a chemical-synthetic film by a foundation treatment for painting such as phosphate treatment or chromate treatment.
  • a proper mixing ratio of chromium compound to be applied in the anodic treating bath is 0.01 to max. 5 weight percent of the above-mentioned water-soluble organic high molecular compound, as calculated in terms of chromium (if below 0.05 weight percent, the deposited coat will be sporadic).
  • An excellent anticorrosiveness can be obtained specially in the range of 0.01 to 1 weight percent.
  • the chromium ion concentration is increased to some degree, a passivating tendency appears at the time of electrodeposition, whereby it becomes difficult to obtain a sufficient thickness (for instance, to 100 mgldm), causing a deterioration of the anticorrosiveness, and if the chromium ion concentration is lowered too much, the chromic acid concentration in the paint coat is reduced, whereby the bridging of the paint coat will be insufficient, which causes the deterioration of working adhesiveness and anticorrosiveness.
  • chromium compounds to be added there may be enumerated water-soluble chromate or bichromate of ammonium, alkali metal, alkaline earth metal, or the third group metal, Practically chromates or bichromates of ammonium, magnesium, strontium, gallium, aluminum or the like are used.
  • the treating bath containing 1 to 30 percent of organic high molecular compound (in terms of the non-volatile part) is practically used, but is not subjected to a particular limitation from the point of the formation of the coat.
  • the pH value of the treating bath is used mainly in the alkaline state.
  • the pH value which is most suitable for practical use is about 8.0.
  • the content of the organic high molecular compound in terms of the non-volatile part
  • the viscosity of the surface coat of the article taken out from the treating bath will become too high, while if the content is below 1 weight percent, the efficiency of electrodeposition will be deteriorated.
  • the concentration of water-soluble resin of the electrodepositing paint suitable for practical use is in the range of 5 to 30 weight percent, preferably l0 to 15 weight percent. if the concentration of the vehicle exceeds 30 weight percent, the viscosity of the paint will increase rapidly and the painting loss will increase and also the minuteness of the coat will be lost. On the other hand, if the concentration of the vehicle is below 5 weight percent, the Coulombs efficiency will be remarkably reduced, the thickness of the paint coat obtained at a normal electrodeposition voltage will become thin, resulting in the reduction of the anticorrosiveness.
  • the electrodeposited coat is required to be of such a thickness that it can be dried in a short period of time by drying (hot wind-drying or compulsive wind-drying) which is to be carried out after rinsing subsequent to the electrodeposition. That is, the electrodeposition should be carried out to such a degree that the resultant coat may reach the thickness of max. 150 mg/dm, desirably 20 to mg/dm
  • the electrodeposition is followed by rinsing and drying, and thereupon the final painting by a solvent-soluble or water-soluble paint is carried out.
  • thermosetting acrylic resin series vinyl-denatured acrylic resin series
  • alkyd-denatured resin series vinyl chloride resin series
  • denatured alkyd resin series vinyl-denatured acrylic resin series paints show the best results in adhesiveness and anticorrosiveness.
  • a steel sheet 1 loosened by an uncoiler 2 is transferred through a guide roll 3 and a pinch roll 4 to a vessel 5 for degreasing and hotwater rinsing, wherein physical and chemical surface regulations are carried out, and then transferred through a roll 6 made of nylon series resin to a bonderising vessel 7.
  • the steel sheet 1 is then passed through a machine 8 for electrophoretic painting, wherein the water-soluble paint is regulated to be of a concentration suitable for the electrophoretic painting (for instance, to the concentration of about 15 weight percent), and there is applied an electric current of a determined voltage turned to a coil speed of the line so that an amount of the paint deposited on the steel sheet is l0 to IOOmg/dm.
  • a machine 8 for electrophoretic painting wherein the water-soluble paint is regulated to be of a concentration suitable for the electrophoretic painting (for instance, to the concentration of about 15 weight percent), and there is applied an electric current of a determined voltage turned to a coil speed of the line so that an amount of the paint deposited on the steel sheet is l0 to IOOmg/dm.
  • any paint of the acrylic ester series, phenol alkyd series and the like may be used.
  • the steel sheet is coated with a determined water-soluble paint in the machine 8 for electrophoretic painting, it is then rinsed in a vessel 9 for rinsing and then lightly dried in a drying machine 10, which is provided with a wind box to dry the steel sheet by wind at room temperature.
  • the drying is carried out by properly regulating the amount and temperature of the wind in accordance with the speed of the line.
  • the steel sheet, the undercoating of which has thus been completed, is then subjected to a finish painting according to per se conventional methods, for instance, it is led by guide rolls 1] and 12 to a roll coating machine 13, wherein a finishing is performed.
  • paints of the thermosetting synthetic resins such as phenol, melamine, alkyd, acryl, vinyl chloride and the like, said paints being so diluted by solvents to such a viscosity as suitable for the finishing (for instance, 30 to sec/20 C. according to Fordcup No. 4).
  • the paint as above-mentioned is applied on the steel sheet by regulating distances of the roll coater so that the dried coat has the thickness of l to 30 microns.
  • 14 is a roll coating machine for painting the reverse (however, by carrying out the electrophoretic painting double painting of the reverse may be omitted).
  • the finish-painted steel sheet is passed through a drying oven 15 having a hot wind heated up to a temperature of 150 to 250 C., wherein both the undercoat and the final coat are simultaneously baked.
  • the baked steel sheet is water-cooled in a water-cooling vessel 16 and transferred to a recoiler 18 through a pinch roll 17 to coil the steel sheet.
  • the bonderising step included in the above-mentioned process is a particularly advantageous foundation treatment, but is not a requisite condition. Therefore, it can be replaced by a chromate treatment or any other chemical-synthetic treatment, or it may be even omitted as the case may be. Further, it is, of course, evident that as for the paint for the finishing a water-soluble paint of a kind different from that for the undercoating may be applied.
  • the first additional process is as follows:
  • the steel sheet coated with a zinc layer or zinc alloy layer is subjected to a phosphate treatment or other chemical-synthetic treatment or other coat treatment which has a high electric resistance prior to the electrophoretic painting with a water-soluble paint or waterdispersed paint
  • the method of the present invention is characterized by maintaining the electric insulation resistance at the coat formed on the surface of the galvanized steel sheet by the chemical-synthetic treatment or the coat treatment of a high electric resistance to below 109 cm when effecting the electrodeposition, and then carrying out the final painting on the electrodeposited coat and baking the electrodeposited undercoat and the final coat at the same time.
  • a conductor roll is required as a device for supplying electricity to the metal sheet.
  • an electric current and a voltage to be supplied reach great values, due to the rise in the speed of the successive painting, there occur various troubles between the conductor roll and the material to be electrodeposited such as, for instance, occurrence of arc spots and melting out of the conductor roll.
  • This first additional step is to eliminate these troubles which may be caused at the conductor roll.
  • this additional step will be explained in detail by referring to concrete examples.
  • the painting speed which is in general use, is about 30 to 60 m/min, but a project is afoot to increase the painting speed even up to 100 to 150 m/min.
  • advantages to be obtained by the application of the electrodepositing painting method will be increased, but trouble as above-mentioned will become acute.
  • electrodepositing conditions become more severe, particularly, a greater voltage and electric current will be required.
  • a voltage of about 50 V for 4 seconds an electric current of 2,000 A will be required for 5 dm and 3 foot width.
  • the electric behavior of the coat formed by the pretreatment as a foundation for the electrodepositing painting exerts a great influence on the electrodepositing painting. That is, with an increase in the resistance of the coat formed by a phosphate treatment or chromate treatment the phenomena of arc spots occurring and the conductor roll melting out become remarkable.
  • the features of the first additional step can be concluded as follows: the insulation resistance is kept at less than cm advantageously less than 50. cm at the surface coming into contact with the conductor roll, and the coat to be formed by the foundation treatment is properly regulated in its quality, thickness and water content so that the above-mentioned condition of the insulation resistance may be fulfilled, and then a metal sheet, for instance, a galvanized steel sheet, which has been subjected to the foundation treatment in the controlled manner as above-mentioned, is sufficiently rinsed so that excessive agent used for the foundation treatment does not remain on the treated surface of the metal, and thereupon fully dried by wind or hot wind before the metal is subjected to the electrodepositing painting through the conductor roll to form an undercoat, on the treated surface of the metal.
  • a metal sheet for instance, a galvanized steel sheet
  • the second additional step of the present invention is as follows:
  • the steel sheet coated with a zinc layer or zinc alloy layer is subjected to a phosphate treatment or other chemicalsynthetic treatment or other coat treatment which has a high electric resistance, or not subjected to the above-mentioned treatment, prior to the electrophoretic treatment with a watersoluble paint, the second additional step is characterized in that the supply of electricity should be so regulated that a contact rolling pressure given by the conductor roll on the surface of the galvanized steel sheet or chemical-synthetically treated galvanized steel sheet is more than about 100 kg per 1 meter width of the steel sheet.
  • electrodepositing painting particularly anodic electrodepositing painting
  • it differs from a general metal plating by the following two points: that is, an anodizing and a high treating voltage. Consequently, in this case, special considera tion is to be given to the conductor roll, through which electricity is supplied for the electrodepositing painting of a steel coil. If the rolling pressure between the metal sheet to be treated and the conductor roll is low, there occurs an arc between them, and if water and the like are on the surface of the metal sheet, an electrolytic cell is formed between the conductor roll and the metal sheet, in which the conductor roll acts as the anode, while the metal sheet as the cathode, whereby the melting out of the conductor roll metal occurs.
  • the second additional step of the present invention is to eliminate various troubles connected with the occurrence of an are, which proves a hindrance to the electrodepositing painting.
  • this metal coil is pressed on the conductor roll at the upper part, the side part and the middle part of the latter by using a pressing roll or others.
  • the rolling pressure should be about 100 kg, preferably above 300 kg per one meter width of the coil.
  • a pressing roll for imparting the necessary pressure is not limited to only one roll. A plurality of rolls may be used, as occasion demands. The pressing roll may be replaced by an imposition of a tensile force on the coil.
  • the third additional step of the present invention is as follows:
  • this additional step is characterized in that electricity is supplied while arranging the surface of the conductor roll, which is to be brought into contact with the steel sheet, by removing a melt stuck to the said surface of the conductor roll, which is mainly composed of zinc or zinc oxide, by means of a scraper such as a doctor blade, immediately after the melt has stuck when supplying the electricity.
  • an electric resisting coat is formed on the surface of the strip coil in advance, to which electricity is supplied, the production of sparks between the strip coil and the conductor roll increases, whereby there occurs the trouble of the conductor roll melting out.
  • the strip coil is plated with a metal such as zinc, which has a relatively small surface hardness and a low melting point, and moreover a coat of high electric insulation resistance is formed on the plated surface by a phosphate treatment, or a chromate treatment or other resinous coat forming, there are easily caused a trouble that the plating metal is oxidized and burnt by sparks or is stuck to the surface of the conductor roll, whereby the plated metal layer on the surface of the strip coil is damaged.
  • a metal such as zinc, which has a relatively small surface hardness and a low melting point
  • the third additional step of the present invention is to eliminate the above-mentioned disadvantages by using a very simple means. That is, this step is characterized in that, when carrying out an electrophoretic painting or other electric recoating treatment of a plated metal sheet having an electric resisting coat on its surface, while pressing the conductor roll on the conductor roll, the solidified melt stuck on the surface on the conductor roll when supplying electricity is quickly and continuously scraped off by means of a doctor blade made of, for instance, stainless steel or other metal.
  • the doctor blade is positioned at a region of the surface of the conductor roll which is not brought into contact with the strip coil (for instance, a zinc-plated steel sheet, which is further subjected to a phosphate treatment), while facing the edge of the blade at a proper angle (a), that is, about 10 to 20 to the normal of the conductor roll, then the solidified melt such as zinc oxide spottedly stuck on the surface of the conductor roll can easily and effectively be scraped off by the edge of the doctor blade, while the conductor roll is rotated, consequently a painted steel sheet having a favorable surface condition is obtained, as the electrophoretic painting can thereby be applied on the steel sheet, as it is.
  • a that is, about 10 to 20 to the normal of the conductor roll
  • the following countermeasure is to be taken, such as forming the edge part of the conductor roll with an electric insulating material by providing the edge part of the main body of the conductor roll itself with a rubber or plastic lining layer, so that the width of the surface of the conductor roll, to which an electric current is supplied, may be made narrower than that of the strip coil (for instance, a zinc-plate steel sheet having a coat formed by a phosphate treatment or other electric-insulating coat), advantageously, the former is made 0.9 times as wide as the latter, thereby to eliminate the part of the surface of the conductor roll, where sparks are most produced.
  • Example 1 Example (case) Process and condition 1 2 3 4 kind of steel sheet Cold-rolled steel sheet Hula-dip zine-plated steel Hog-dip zinc-plated steel Galvanized steel sheet.
  • EXAMPLE 2 A galvanized steel sheet having a clean surface was made the anode, while a stainless sheet was used for the cathode. A coat was formed with an interpolar voltage of 80 V in the treating solution of the composition as shown in the following:
  • Copolymer of ammonium acrylate and butyl ester acrylate (ratio of The thus obtained paint coat is a transparent one having a slightly yellow-colored luster and shows no change for 250 hours in a salt water spray test.
  • an insoluble electrodeposited coat is formed on the surface of a galvanized steel sheet, which is proportioned to a time of supplying an electric current, without resulting in a decrease of the electric current and, then by drying the said coat by heating after a simple rinsing or wringing a coat completely uniform and firm and excellent in anticorrosiveness can be obtained.
  • the thus-obtained galvanized steel sheet which was subjected to an electrodepositing treatment is practically used either as a steel sheet having an undercoat as a foundation for a further painting or an anticorrosive steel sheet itself according to more or less amount of the deposit.
  • a colored paint coat may be formed by causing an aqueous agent for dispersing coloring pigments subjected to an anionic activator treatment to co-exist in the treating bath of the present invention.
  • This method is also practically used as a surface treating method which answers the purpose of effecting protection and decoration at the same time.
  • EXAMPLE 5 A galvanized steel sheet subjected to a phosphate treatment was coated with paint by the electrodeposition for the time of 3 to 5 seconds under the conditions of the line speed of 45 to 50 m/min, 40 to 50 V and 4 to 5 A/dm while a rolling pressure of 300 kg per 1 meter of coil width was imposed by means of one roll.
  • the electrodepositing paint was the water-soluble paint for use in the electrodeposition as used in Examples 2 and 3.
  • the bath temperature was 40 to 50 C.
  • the deposition amounted to 30 to 40 mg/dm".
  • the electrodeposition was followed by rinsing and wind-drying.
  • the steel sheet was then coated with acrylvinyl series paint in the thickness of 15 to 25 microns and then baked at 140 to 270 C. for 50 to 60 seconds, and further rinsed again and coiled. After rinsing the steel was coiled. In this example there was seen no occurrence of arc spots and loss of conductor roll by melting.
  • the properties of the product were as follows:
  • the electrodepositing painting was carried out for 3 to successive paintings which comprises the steps of subjecting 5 seconds under the conditions of the line speed 45 to 50 the metal sheet to anelectrophoretic painting with an aqueous /m 4 50 V, nd 4 0 5 A/dm
  • the electrodepositing paint as an undercoating painting, rinsing and wind-drying the paint was a water-soluble acrylic acid series paint as used in nde at formed by the electrophoretic painting and then Examples 2 and 3.
  • Th BIECUOdCpOSlt amounted [O 30 IO 40 subjecting the resultant undercoated metal sheet to a nonmg/ m Immediately f er fining nd wind-drying the final electrophoretic final painting with an organic solvent-soluble coating was carried out with acrylvinyl Series Paint and fired thermosetting paint and thereafter baking the resultant eleca lemperaml'e 140 to 270 C. f 50 to 0 Seconds After trodeposited undercoat and final coat together in a single bakwater cooling, it was coiled.
  • Step of arc spots and loss of conductor rolls by melting there was found no occurrence i Step of arc spots and loss of conductor rolls by melting, and the 2 A method f manufacturing a painted metal sheet by P has the following Properties: successively painting flat metal sheet or strip coil which is plated with zinc or zinc alloy, which comprises the steps of Sa1 Water B y resistance excellent 500 his) subjecting the said metal sheet or strip coil to an elecmi cl giifiz c liiion excellent (for 500 hrs) trophoretic painting with a water-soluble acrylic resin series resistnce Excellent paint as a underpamting, rinsing and wind-drying the unwolking adheslveness 2O dercoat formed by the electrophoretic painting, and imggggsngnukgfno cm 3:23:22: mediately thereupon non-electrophoretically painting the un- Bending 3 exceuem dercoated metal sheet or strip coil with at least one kind of EXAMPLE 7
  • a method for manufacturing a painted steel sheet or strip rinsing and wind-drying an acrylvinyl series paint was painted 30 coil by successively painting steel sheet or strip coil which is in a thickness of i5 to 25 microns by using a roll coater and plated with zinc or zinc alloy, which comprises the steps of baked at 140 to 27 C.
  • Viscosity (30%) 700 CPS. 3000 CPS. 6000 CPS. Ammonium chromate. O.l0%. 0.
  • the method of the present invention is a trodepositing treating bath, said bath consisting of a watertwo-coating and one-baking method, the paint does not come soluble resin, which is composed of acrylic ester and/or turbid in its color, but shows an excellent adhesiveness and methacrylic ester and its ammonium salt or amine salt, and a corrosion resistance, because in the method of the present inwater-soluble chromium compound added in an amount of vention an aqueous electrophoretic paint, which is essentially about 0.01 to 5.0 weight percent to the said resin, rinsing and of the property of being very easily dried, is used as an undrying the undercoat formed by the electrophoretic painting, dercoating paint and then a water-soluble or solvent-soluble when the coat is deposited in an amount of 150 mg/dm and paint is applied as a final paint and thereupon is baked and immediately thereupon non-electrophoretically painting the dried for hardening.
  • soluble resin which is composed of acrylic ester and
  • the undercoat and the final undercoated steel sheet or strip coil with at least one kind of coat, or more than two coats, as occasion calls may be baked thermosetting paint selected from the group consisting of simultaneously at one time, not only there is required only one phenol resin series, melamine resin series, alkyd resin series, baking furnace but also the painting line may be remarkably 7O acrylic resin series and vinyl resin series or their copolymers as shortened in length.
  • the final painting and baking the resultant electrodeposited tained by the method of the present invention that the painting undercoat and thermosetting final coat at the same time in at operation can easily be managed and thereby the yield of single king p and ng the resultant P products may highly be improved. 4.
  • a method for manufacturing a painted steel sheet or strip coil by successively painting steel sheet or strip coil, which is plated with zinc or zinc alloy which comprises the steps of subjecting the steel sheet or strip coil to a chemical-synthetic treatment to obtain a coat having a high electric resistance, then subjecting the chemical-synthetically treated steel sheet or strip coil to an electrophoretic painting with a water-soluble paint or a water-dispersed paint, while keeping the electric resistance of the chemical-synthetically formed coat to below 100 cm rinsing and wind-drying the undercoat formed by the electrophoretic painting and then subjecting the resultant undercoated steel sheet or strip coil to a non-electrophoretic final painting with an organic solvent-soluble thermosetting paint as the final painting and thereafter baking the resultant undercoat electrodeposited and the thermosetting final coat together in a single baking step.
  • a method for manufacturing a painted steel sheet or strip coil by successively painting steel sheet or strip coil which is plated with zinc or zinc alloy which comprises the steps of subjecting steel sheet or strip coil to an electrophoretic painting after optional chemical-synthetical treatment, in advance, while regulating the contact rolling pressure between the steel sheet or strip to be treated and a conductor roll so that it is above about 100 kg per one meter width of the steel sheet or strip coil, rinsing and wind-drying the undercoat formed by the electrophoretic painting and then subjecting the resultant undercoated steel sheet or strip coil to a non-electrophoretic final painting with an organic solvent-soluble thermosetting paint and thereafter baking the resultant undercoat electrodeposited and the thermosetting final coat together in a single baking step.
  • a method for manufacturing a painted steel sheet or strip coil by successively painting steel sheet or strip coil, which is plated with zinc or zinc alloy which comprises the steps of subjecting the steel sheet or strip coil to a chemicalsynthetical treatment to obtain an undercoat as a foundation for painting which has high electric resistance, and then subjecting the chemical-synthetically treated steel sheet or strip coil to an electrophoretic painting with a water-soluble paint or a water-dispersed paint, while removing solidified melt stuck to the surface of a conductor roll, to which electricity is supplied, such as zinc or zinc oxide, by means of a doctor blade, immediately after it has stuck to the surface of the conductor roll and arranging the surface of the conductor roll, which is brought into contact with the said steel sheet or strip coil, rinsing and wind-drying the resultant undercoat formed by the electrophoretic painting and then subjecting the resultant undercoated steel sheet or strip coil to a non-electrophoretic final painting with an organic solvent-soluble thermosetting paint as the final painting and thereupon

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Chemical Treatment Of Metals (AREA)
  • Electroplating Methods And Accessories (AREA)
  • Other Surface Treatments For Metallic Materials (AREA)
US734801A 1967-06-05 1968-06-05 Method for manufacturing painted metal sheet Expired - Lifetime US3663383A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP3590067 1967-06-05
JP1967050450U JPS463008Y1 (enrdf_load_stackoverflow) 1967-06-12 1967-06-12
JP3914767 1967-06-19

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US (1) US3663383A (enrdf_load_stackoverflow)
BE (1) BE716107A (enrdf_load_stackoverflow)
DE (1) DE1771533B2 (enrdf_load_stackoverflow)
GB (1) GB1235176A (enrdf_load_stackoverflow)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3998716A (en) * 1974-06-03 1976-12-21 Inmont Corporation Method of applying coatings
US4083763A (en) * 1968-07-08 1978-04-11 Nippon Steel Corporation Method for manufacturing colored metal sheets
US4175018A (en) * 1977-01-19 1979-11-20 Ppg Industries, Inc. Method of electrocoating
US4191624A (en) * 1977-10-06 1980-03-04 Desoto, Inc. Electrodeposition of high molecular weight copolymers
US4268542A (en) * 1975-12-26 1981-05-19 Dai Nippon Toryo Co., Ltd. Process for forming multi-layer coatings
US4576694A (en) * 1981-05-09 1986-03-18 Mitsubishi Denki Kabushiki Kaisha Method for producing electrically insulated conductor
US5104507A (en) * 1989-10-02 1992-04-14 Illinois Tool Works Inc. Anodic-cathodic coating for fasteners
US5296127A (en) * 1986-04-25 1994-03-22 Saunders William T Composite-coated flat-rolled sheet metal manufacture
WO2002070147A3 (en) * 2001-03-02 2004-12-09 Ppg Ind Ohio Inc Apparatus and methods for continuously electrocoating metal blanks and/or coiled metal substrates
US20090011131A1 (en) * 2007-07-06 2009-01-08 Ama Precision Inc. Method for treating surface of heat dissipating module
US20160175882A1 (en) * 2014-12-17 2016-06-23 Whirlpool Corporation Transparent tinted coating for appliance exterior panels to allow for tinted surface patterns and a process for application of coating
US9530109B2 (en) * 2010-09-28 2016-12-27 International Business Machines Corporation Iterative pattern generation algorithm for plate design problems

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3447257A1 (de) * 1984-12-22 1986-06-26 Basf Farben + Fasern Ag, 2000 Hamburg Verfahren zur mehrschichtigen kathodischen nass-in-nasslackierung von metallisch leitfaehigen substraten
GB2174315B (en) * 1985-05-03 1988-10-19 Cooper Coated Coil Ltd Improvements relating to pre-coated metal sheet suitable for use in the manufacture of bakeware and other products intended for use at high temperatures
US5376457A (en) * 1993-08-19 1994-12-27 Volvo Gm Heavy Truck Corporation Vehicle coating process

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1405550A (fr) * 1963-07-30 1965-07-09 Perfectionnements apportés à l'obtention de revêtements non métalliques par électrophorèse
GB1073965A (en) * 1963-07-30 1967-06-28 Georg Peter Borkon Improvements in and relating to methods of producing non-metallic coatings
US3362899A (en) * 1966-01-04 1968-01-09 Ford Motor Co Method of maintaining bath composition in continuous electrodeposition process
US3408278A (en) * 1963-10-04 1968-10-29 Porter Paints Ltd Painting process wherein a conductive undercoat is electrophoretically deposited
US3437574A (en) * 1964-08-31 1969-04-08 Kansai Paint Co Ltd Anticorrosive treatment of zinc and metallic materials coated with zinc
US3441489A (en) * 1965-10-22 1969-04-29 Ppg Industries Inc Method for removing gas film formed during electrodeposition

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE971564C (de) * 1952-03-26 1959-02-19 Metallgesellschaft Ag Verfahren zum Auftragen von Deckschichten auf Grundschichten im elektrostatischen Feld
FR1401301A (fr) * 1964-04-20 1965-06-04 Perfectionnements à l'obtention de dépôts de peintures, laques ou analogues par électrophorèse

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1405550A (fr) * 1963-07-30 1965-07-09 Perfectionnements apportés à l'obtention de revêtements non métalliques par électrophorèse
GB1073965A (en) * 1963-07-30 1967-06-28 Georg Peter Borkon Improvements in and relating to methods of producing non-metallic coatings
US3408278A (en) * 1963-10-04 1968-10-29 Porter Paints Ltd Painting process wherein a conductive undercoat is electrophoretically deposited
US3437574A (en) * 1964-08-31 1969-04-08 Kansai Paint Co Ltd Anticorrosive treatment of zinc and metallic materials coated with zinc
US3441489A (en) * 1965-10-22 1969-04-29 Ppg Industries Inc Method for removing gas film formed during electrodeposition
US3362899A (en) * 1966-01-04 1968-01-09 Ford Motor Co Method of maintaining bath composition in continuous electrodeposition process

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4083763A (en) * 1968-07-08 1978-04-11 Nippon Steel Corporation Method for manufacturing colored metal sheets
US3998716A (en) * 1974-06-03 1976-12-21 Inmont Corporation Method of applying coatings
US4268542A (en) * 1975-12-26 1981-05-19 Dai Nippon Toryo Co., Ltd. Process for forming multi-layer coatings
US4175018A (en) * 1977-01-19 1979-11-20 Ppg Industries, Inc. Method of electrocoating
US4191624A (en) * 1977-10-06 1980-03-04 Desoto, Inc. Electrodeposition of high molecular weight copolymers
US4576694A (en) * 1981-05-09 1986-03-18 Mitsubishi Denki Kabushiki Kaisha Method for producing electrically insulated conductor
US5296127A (en) * 1986-04-25 1994-03-22 Saunders William T Composite-coated flat-rolled sheet metal manufacture
US5104507A (en) * 1989-10-02 1992-04-14 Illinois Tool Works Inc. Anodic-cathodic coating for fasteners
WO2002070147A3 (en) * 2001-03-02 2004-12-09 Ppg Ind Ohio Inc Apparatus and methods for continuously electrocoating metal blanks and/or coiled metal substrates
US20090011131A1 (en) * 2007-07-06 2009-01-08 Ama Precision Inc. Method for treating surface of heat dissipating module
US9530109B2 (en) * 2010-09-28 2016-12-27 International Business Machines Corporation Iterative pattern generation algorithm for plate design problems
US10108913B2 (en) 2010-09-28 2018-10-23 International Business Machines Corporation Iterative pattern generation algorithm for plate design problems
US20160175882A1 (en) * 2014-12-17 2016-06-23 Whirlpool Corporation Transparent tinted coating for appliance exterior panels to allow for tinted surface patterns and a process for application of coating
US10052655B2 (en) * 2014-12-17 2018-08-21 Whirlpool Corporation Transparent tinted coating for appliance exterior panels to allow for tinted surface patterns and a process for application of coating

Also Published As

Publication number Publication date
DE1771533A1 (de) 1972-02-24
DE1771533B2 (de) 1981-04-23
BE716107A (enrdf_load_stackoverflow) 1968-11-04
GB1235176A (en) 1971-06-09

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